Motor vehicle vacuum pump

ABSTRACT

A motor vehicle vacuum pump includes a pump housing which encloses a pump chamber, a pump rotor bearing, a pump rotor, a coupling unit rotationally fixed to the pump rotor which connects the pump rotor to a drive shaft, and a lubricant supply assembly which lubricates the pump chamber, the pump rotor bearing and/or the coupling unit. The pump housing has a lubricant inlet opening. The pump rotor is arranged in the pump chamber via the pump rotor bearing. The lubricant supply assembly includes a lubricant outlet opening and a lubricant supply duct which is arranged in the pump housing so that a lubricant is pumpable from the lubricant inlet opening towards the pump chamber, the pump rotor bearing and/or the coupling unit, to the lubricant outlet opening. A seal element is arranged in a region of, and a filter element is arranged in, the lubricant inlet opening, respectively.

CROSS REFERENCE TO PRIOR APPLICATIONS

This application is a U.S. National Phase application under 35 U.S.C. § 371 of International Application No. PCT/EP2016/066731, filed on Jul. 14, 2016. The International Application was published in German on Jan. 18, 2018 as WO 2018/010793 A1 under PCT Article 21(2).

FIELD

The present invention relates to a motor vehicle vacuum pump comprising a pump housing that encloses a pump chamber in which a pump rotor with at least one movably mounted pump rotor blade is rotatably mounted via pump rotor bearing, the pump rotor being directly or indirectly connectable to a drive shaft via a coupling unit which is rotationally fixed to the pump rotor, wherein a lubricant supply assembly is provided to lubricate the pump chamber and/or the pump rotor bearing and/or the coupling unit, wherein the lubricant supply assembly has at least one stationary lubricant supply duct in the pump housing, through which duct the lubricant can be pumped through the supply duct from a lubricant inlet opening of the pump housing in the direction of the pump chamber and/or the pump rotor bearing and/or the coupling unit to a lubricant outlet opening, wherein, a seal element is provided in the region of the lubricant inlet opening and a filter element is provided in the lubricant inlet opening.

BACKGROUND

WO 2013/024117 A2 describes a mechanical motor vehicle vacuum pump which comprises a lubricant supply assembly where the liquid lubricant is transferred through a stationary lubricant supply duct in the pump housing via a lubricant outlet opening into a lubricant duct extending in the axial direction in the hollow-cylindrical surface of the pump housing, whereby a sliding mounting of the pump rotor is provided. The lubricant supply assembly provides a lubrication of the running surface of the at least one rotor blade in the pump housing. A lubricant pump is provided for this purpose outside the vacuum pump. The lubricant pump pumps a lubricant to a lubricant inlet opening. This vacuum pump is rotationally fixedly connected to the crankshaft or the drive shaft of the internal combustion engine via a plug-in coupling assembly. The plug-in coupling assembly is composed of plug-in coupling elements configured complementarily to each other which comprise one or a plurality of pawls that engage with corresponding recesses of the respective other plug-in coupling element.

A filter element is provided in the region of the lubricant inlet opening to protect the lubricant supply assembly from contamination. A seal element is also provided to prevent a lubricant from unintentionally escaping to the outside of the lubricant supply assembly. This configuration is relatively complex and sensitive to dynamic stresses with regard to sealing.

SUMMARY

An aspect of the present invention is to provide a motor vehicle vacuum pump with a lubricant supply which has a simple configuration which avoids the above mentioned drawbacks.

In an embodiment, the present invention provides a motor vehicle vacuum pump which includes a pump housing configured to enclose a pump chamber, a pump rotor bearing, a pump rotor comprising at least one movably mounted pump rotor blade, a coupling unit which is rotationally fixed to the pump rotor and which is configured to directly or indirectly connect the pump rotor to a drive shaft, and a lubricant supply assembly configured to lubricate at least one of the pump chamber, the pump rotor bearing and the coupling unit. The pump housing comprises a lubricant inlet opening. The pump rotor is arranged in the pump chamber via the pump rotor bearing. The lubricant supply assembly comprises a lubricant outlet opening and at least one stationary lubricant supply duct which is arranged in the pump housing and which is configured so that a lubricant can be pumped therethrough from the lubricant inlet opening of the pump housing in a direction of at least one of the pump chamber, the pump rotor bearing and the coupling unit, to the lubricant outlet opening. A seal element is arranged in a region of the lubricant inlet opening. A filter element is arranged in the lubricant inlet opening. The seal element the filter element are formed as a combined seal/filter unit.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is described in greater detail below on the basis of embodiments and of the drawings in which:

FIG. 1 shows a longitudinal section of a motor vehicle vacuum pump according to the present invention; and

FIG. 2 shows an enlarged diagram of a combined seal/filter unit of the motor vehicle vacuum pump of FIG. 1.

DETAILED DESCRIPTION

The present invention provides that the seal element and the filter element are configured as a combined seal/filter unit. The function of the lubricant supply assembly is thereby provided in a particularly simple and inexpensive manner. A lubrication of the pump chamber, of the pump rotor bearing and/or of the coupling unit may be provided thereby. The pumps may be both mechanical and electrical vacuum pumps.

In an embodiment of the present invention, the seal element can, for example, be arranged on an edge element of the filter element. A conventional filter element can thus be used to create the combined seal/filter unit. A filter element is here to be understood as a single- or multi-part filter element.

The combined seal/filter unit can alternatively be formed as a single piece. It is here particularly advantageous when the seal element is injection-molded to the filter element.

In an embodiment of the present invention, the filter element can, for example, comprise a filter nozzle which serves to restrict the flow rate.

In an embodiment of the present invention, the pump rotor outer surface can, for example, be mounted in a hollow-cylindrical surface of the pump housing, wherein the lubricant supply assembly is configured so that the lubricant outlet opening is at least temporarily fluidically connected to a lubricant duct extending in the axial direction in the hollow-cylindrical surface. The lubricant supply assembly may of course be of a different configuration. Further ducts and openings may in particular be provided.

In an embodiment of the present invention, the lubricant duct can, for example, open towards the pump chamber so that a lubricant can be transferred to the pump chamber. Lubrication of the running surface is thereby provided in a simple manner. It is here advantageous when the lubricant duct flares towards the lubricant duct.

An exemplary embodiment of the present invention is described in detail below under reference to the drawings.

FIG. 1 schematically illustrates a vacuum pump assembly which is essentially composed of a motor vehicle vacuum pump 2, an internal combustion engine 4, and a lubricant pump 6 associated with the internal combustion engine 4. The motor vehicle vacuum pump 2 is here mechanically rotationally coupled to a crankshaft or a drive shaft of the internal combustion engine 4 via a plug-in coupling assembly 8. The motor vehicle vacuum pump could, however, also be configured as an electrical vacuum pump. Such an electrical vacuum pump could also be directly connected to a drive shaft without interposition of a coupling assembly. The motor vehicle vacuum pump 2 serves, for example, to provide an actuatoric vacuum for different ancillary units of the motor vehicle, e.g., for a pneumatic brake force booster. The lubricant pump 6 delivers the liquid lubricant for the lubricant supply of the internal combustion engine 4 and the lubricant supply of the motor vehicle vacuum pump 2.

The motor vehicle vacuum pump 2 is a so-called vane-type pump and comprises a pump housing 10 which is essentially composed of a housing body 12 and a housing cover 14. A pump rotor 16 is mounted in the pump housing 10. The pump rotor 16 rotates about a longitudinal axis and has a movably mounted pump rotor vane 18. For producing a vacuum to be made available to a consumer, both ends of the eccentrically mounted pump rotor vane 18 are guided across a running surface 20 of the housing body 12 so that air taken in via an air inlet branch 22 is compressed in a pump chamber 23, which is enclosed by the pump housing 10 and divided into two portions by the pump rotor 16, and discharged via an air outlet branch (which is not shown in the drawings).

The pump rotor 16 has a pump rotor outer surface 24 which, together with a hollow-cylindrical surface 26 of the pump housing 10, forms a sliding bearing assembly 28. A lubricant supply assembly 30 is provided which is fluidically connected to the lubricant pump 6 to provide a lubricant supply of the sliding bearing assembly 28 and the running surface 20 of the housing body 12.

The pump housing 10 comprises a flange surface 32 which rests upon a suitable part of the internal combustion engine. For coupling with a drive shaft (which is not shown in the drawings), a coupling unit 34 of the plug-in coupling assembly 8 is provided which is rotationally fixedly coupled with the pump rotor 16 in a known manner.

A lubricant inlet opening 36 is arranged in the flange surface 32 to provide a tightly sealed and dirt-free lubricant supply assembly which also withstands high dynamic stresses. A combined seal/filter unit 38 is press-fitted in the lubricant inlet opening 36. As is in particular shown in FIG. 2, in the present exemplary embodiment, the combined seal/filter unit 38 is composed of a filter element 40 which, in the present exemplary embodiment, essentially comprises a filter nozzle 41 to restrict the flow rate, an edge element 42, and a clicked-on filter disk 44. An annular seal element 45 is put onto the edge element 42. The combined seal/filter unit 38 can alternatively be formed as a single piece. The single-piece configuration is generally a single-piece configuration of the edge element 42 of the filter element 40 and the annular seal element 45, wherein the annular seal element 45 is injection-molded to the filter element 40. The filter disk 44 can, however, also be integrated by a die casting.

The lubricant is thus pumped by the lubricant pump 6 via the lubricant inlet opening 36 with the combined seal/filter unit 38 into an adjoining lubricant supply duct 46 of the lubricant supply assembly 30 (which is illustrated by a solid line). The lubricant supply duct 46 has a lubricant outlet opening 48 which, upon rotation of the pump rotor 16, is at least temporarily fluidically connected to a lubricant duct 50 extending in the axial direction in the hollow-cylindrical surface 26. The sliding bearing assembly 28 can thereby be adequately supplied with a lubricant.

Due to the fact that the lubricant duct 50 is open and flared towards the pump chamber 23, a lubricant is fed into the pump chamber and lubricates the running surface 20 in a known manner and returns to the lubricant pump 6 via an outlet (not shown in the drawings), which is illustrated by a dashed line.

The coupling unit 34 can be incorporated in the lubricant supply assembly if desired. Solely a lubrication of the pump rotor bearing assembly can, for example, be performed in the case of a so-called dry-running vacuum pump.

The present invention is not limited to embodiments described herein; reference should be had to the appended claims. 

What is claimed is: 1-7. (canceled)
 8. A motor vehicle vacuum pump comprising: a pump housing configured to enclose a pump chamber, the pump housing comprising a lubricant inlet opening; a pump rotor bearing; a pump rotor comprising at least one movably mounted pump rotor blade, the pump rotor being arranged in the pump chamber via the pump rotor bearing; a coupling unit which is rotationally fixed to the pump rotor and which is configured to directly or indirectly connect the pump rotor to a drive shaft; a lubricant supply assembly configured to lubricate at least one of the pump chamber, the pump rotor bearing, and the coupling unit, the lubricant supply assembly comprising a lubricant outlet opening and at least one stationary lubricant supply duct which is arranged in the pump housing and which is configured so that a lubricant can be pumped therethrough from the lubricant inlet opening of the pump housing in a direction of at least one of the pump chamber, the pump rotor bearing, and the coupling unit, to the lubricant outlet opening; a seal element arranged in a region of the lubricant inlet opening; and a filter element being arranged in the lubricant inlet opening, wherein, the seal element the filter element are formed as a combined seal/filter unit.
 9. The motor vehicle vacuum pump as recited in claim 8, wherein, the filter element comprises an edge element, and the seal element is arranged on the edge element of the filter element.
 10. The motor vehicle vacuum pump as recited in claim 8, wherein the combined seal/filter unit is formed as a single piece.
 11. The motor vehicle vacuum pump as recited in claim 10, wherein the seal element is injection-molded to the filter element.
 12. The motor vehicle vacuum pump as recited in claim 8, wherein the filter element comprises a filter nozzle.
 13. The motor vehicle vacuum pump as recited in claim 8, further comprising: a pump rotor outer surface; and a lubricant duct, wherein, the pump housing further comprises a hollow-cylindrical surface, the pump rotor outer surface is mounted in the hollow-cylindrical surface of the pump housing, the lubricant duct is configured to extend in an axial direction in the hollow-cylindrical surface, and the lubricant supply assembly is further configured so that the lubricant outlet opening is at least temporarily fluidically connected to the lubricant duct.
 14. The motor vehicle vacuum pump as recited in claim 13, wherein the lubricant duct is further configured to open towards the pump chamber so that the lubricant can be transferred into the pump chamber.
 15. The motor vehicle vacuum pump as recited in claim 14, wherein the lubricant duct is further configured to flare towards the pump chamber. 